Re: Solid sprites
It depends on the script you are using to move your sprite. You need something in that script that stops it from working if it can sense their is whatever you are using as a wall in front of it.
Web-spinning Spider: http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure: http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484